It is possible that AML patients that have chromatin‐spliceosome mutations may have had a prodromal MDS period even if they did not necessarily meet the formal criteria for AML with myelodysplasia‐related changes (AML‐MRC).35 In fact, a study of 194 patients with rigorously defined s‐AML found that mutations in SF3B1, SRSF2, U2AF1, ZRSR2, ASXL1, EZH2, BCOR, or STAG2 was >95% specific for the diagnosis of s‐AML.24 When mutations in these genes were found in de novo AML, they conferred the same poor prognosis as seen in s‐AML. The gene discussed is U2AF1; the disease is myelodysplastic syndrome.